Duplex electrical wall receptacle



Nov. 18, 1952 Filed Aug. l, 1951 w. E: PARxsH ETAL 2,618,677

DUPLEX ELECTRICAL WALL RECEPTACLE 2 SHEETS-SHEET l NOV. 18, 1952 Aw, E, PARlSH ETAL 2,618,677

DUPLEX ELECTRICAL WALL RECEPTACLE Filed Aug. l, 1951 2 SHEETS-SHEET 2 INVENTORS;

Patented Nov. 18, 1952 UNITED STATES iar'EN'l OFFICE DUPLEX ELECTRICAL WALL RECEPTACLE Application August 1, 1951, Serial No. 239,770

(Cl. l73-330) 3 Claims. l

This invention relates to receptacles for electrical plugs, and is of the type commonly known as a convenience outlet. These receptacles are installed in the Wall structures of homes and offices for the reception of plugs attached to the cords of lamps and other electrical appliances.

More particularly, this invention relates to a receptacle or^ the type referred to of the duplex type-that is, the receptacle is adapted to accommodate two plugs at the same time, and further the structure herein disclosed is adapted to be detachably mounted in the opening or" a conduit outlet box, and further the receptacle is of the type provided with a third contact to receive a grounding Contact on the plug.

The invention has as an object a receptacle or" the type referred to embodying a novel construction by which the receptacle may be manufactured and parts assembled at low cost, and which is particularly serviceable in use.

The invention consists in the novel features in the combinations and constructions hereinafter set forth and claimed.

in describing this invention, reference is had to the accompanying drawings in which like characters designate corresponding parts in all the views.

Figure 1 is a top plan View of a receptacle ernbodying our invention.

Figure 2 is a lengthwise sectional vie on line 2 2, Figure 1.

Figure 3 is a bottom plan View of the structure shown in Figure 1.

Figure 4 is a top plan View 0f the base of the receptacle with the cover removed.

Figure 5 is a plan View of one Contact plate.

Figure 6 is a View similar to Figure 5 of the second contact plate.

Figure 7 is a View taken on line 1 -l, Figure 5.

Figure 8 is a side elevational view of the grounding contact.

Figure 9 is a View taken on line corresponding to line 99, Figure 2.

The receptacle consists of a body or base l) elongated in general form and being rounded at its ends. The under side of the body is formed with a rectangular recess H adjacent each end of the body and in which are mounted nut bers l2 threaded on screws I3. When the screws taken are tightened, the inner ends of the nuts l2 enf gage an inclined wall I4, and the nuts are urged outwardly into engagement with the conduit cut-- let box and by this manner, the base Hi is detachably secured to the open side of the box.

The plug receiving contacts are mounted on Contact carrying plates l5, i9. The medial or center portion 2B of these plates is apertured, as at 2|, to permit the plates to be mounted upon a post 22 extending upwardly from the center oi the body IG, and the portions ZS extend transversely across the body and merge with end portions Qi, i5, which extend lengthwise of the body and in opposite directions from the center ther.,- of. The medial portion 2!) of one of the plates, such as IE?, is oiset downwardly and the medial portion of the plate lil is olset upwardly whereby, when the contact plates are positioned upon the post 22, there is a space between the medial portions 23 of the plate for the reception of a washer E@ of insulating material, see Figure 2.

The end portions 25 of each contact plate is formed with a depending terminal portion 2E extendinfr downwardly through apertures 2S formed in the base and provided at their lower end with binding screws Each of these depending terminal portions 28 is positioned in proximity to projections 32 which extend downwardly from the under side of the body l@ and which are located on the sides of the contact portions 23 opposite to the heads of the binding screws With this arrangement, each of the contact plates it, I9, is connected to the feed wires. Each of the plates is provided at each end with upwardly extending plug receiving contacts 35 of conventional blade construction for the reception of plug contacts arranged in either tandem or parallel relation.

A grounding Contact is located in proximity to each pair of the contacts 36. These contacts consist of a bottom portion 6i@ positioned in a slot ci formed in the top surface of the body id adjacent each end thereof and the contacts have an upwardly extending portion [i2 terminating in a transversely extending portion :i3 formed on a curvature, as shown in Figure 4. The bottom portion t@ is apertured to receive the screws which function to hold the contacts in place and to detachably secure the receptacle body to the outlet box, as previously explained. The ccntacts 38, 43, are enclosed by a cover t formed with compartments 41 for the contacts 3E, and with compartments 48 for the contacts 43. The top of the cover is apertured or slotted, as at 49, with the slots arranged in registration with the contacts for guiding the prongs or contacts of the plug into engagement therewith. The covers are also apertured, as at 59, over the compartments 43 for guiding the grounding prongs of the plug into engagement with the contacts 43. The cover 46 is detachably secured to the body by a screw 52 arranged centrally in the cover and threading into the post 22. The compartments i8 and the cover :i6 are formed with vertically extending ribs 55 arranged in proximity to the ends of the compartments. The compartments are also formed with a pair of vertically extending ribs 56 located in the central portion of the compartments and confronting the ribs 55. The transversely extending portion of the ground contact is positioned between the ribs 55, 55, with the ends of the contact engaging the ribs 55, and the central portion of the contact engagingntjhe ribs 56 in the absence of a plug positioned in the receptacle.

The ground contact is formed of spring 'metal' and curved, as shown in Figures 4"and'9. The function of the ribs 55 is to'avo'idthe' possibility of the contact springing outwardly an amount to interfere with the insertion of the ground prong of the plug in the aperture 59. With theends of the contact supported bythe ribs 55, the central portion ofthe contact is yieldingly pressed againstthe ground prong of the yplug when the same is inserted through the aperture 5G, thus assuring a proper and 'adequate engagement between thev prong of the-plug and the contact. A

The v'contact plates I8, 19,' are'mounted on the post 22 in superimposed relationy and separated by the insulating washer "26. 'The contact plates are iixedly secured to the post by a grip washer 5d formed 'with inwardly extending radialprojections 55. The vwasher is 'of dish'ed or conical formation and is'appliedto 'the post "with the `p'rc'ijections' extending orinclined upwardly.

These projections frictionally engage the post and as the washer is pressed downwardly against the medial-portion-2i! of the upperplate I8, the projections "'55 4are caused "to "contact tightly against the post 22'as will be apparent, and serve to prevent any upward axial'movement ofthe plates from' the body.

said post and being insulated ir'ornea'ch other,`

each of said` plates having aurnedial portionextending transverselyof'the body Iand 'merging with end lportions"extending"lengthwise or the body'in opposite directions from said post, plug receiving contacts mounted on the 'end portions of each' of Vsaid plates andfextendingupwardly therefrom, a terminal portionextending downwardly from one end portion of each contact plate through said apertures respectively, `a friction grip washer formed with radial inwardlycxtending projections engaging f said post and being operable to retain said plates thereon against `in superimposed relation on said post, each of said vplates 'havinga medial portion extending transversely of the body and merging with end portions extending lengthwise of the body in opposite vdirections from said post, one plate having 'its'medial portion offset downwardly from the end portionsfsaid other plate having its medial portion oiset upwardly from the end portions, a washer of insulating material positioned on the post between the medial portions of the contact plates, plugreceivin'g contacts mounted'cn the end portions 'of each' ci said plates tand' lextending upwardly therefrom;aterminalportin xtendi'ng downwardly fr'orn I' one end-A portion of each contact plate through said'apertures respectix/engaA friction 'grip washer' formed *with-radial inwardly'extending projections 'engaging saidpost and being operable' toV retain'fsaid plates Vthereon against; axialV movement thereof ,"a vcover r'men'iber 'detachably secured to the bodyiand enclosing vsaid `plug receiving contacts and being'forrried with apertures arranged in registration therewith.

3. A duplex receptacle comprising'abodya rvcover detachably mounted von'tiie body,"a"'c`ontact mounted on the' body and 'extending upwardly therefrom, the upper "end o i` 'said contact v'having a plug contact engaging portion extendingjtransversely of the bodyjsaid cover' being formed with a compartment to receivesaid'contact, sa'idcompartment having Aa pair 'ofribs engaging one side of the transversely extending portioncf the' contact at the ends thereof,` said compartment being also formed with affpairofvertically extending Vribs engaging the' opposite side' of the'contact in Vproximity to the center" tl'iereof,V 'and the top wall of said' compartment'being formed with aplug receiving aperture arranged in registrationivith said vertically extending ribs. I l

. WIL-LARD' Ai=Aru-`s'5H.

RAY'WF. LESTER.

REFERENCESCITED The ffollowing references are :ofr'eeord' inthe fileof this patent:

UNITED STATES PATENTS Frank Man-"26,` 1935 

